closing panes

src/public/app/widgets/buttons/close_pane_button.js

@@ -0,0 +1,18 @@
+import ButtonWidget from "./button_widget.js";
+
+export default class ClosePaneButton extends ButtonWidget {
+    isEnabled() {
+        return super.isEnabled()
+            // main note context should not be closeable
+            && this.noteContext && !!this.noteContext.mainNtxId;
+    }
+
+    constructor() {
+        super();
+
+        this.icon("bx-x")
+            .title("Close this pane")
+            .titlePlacement("bottom")
+            .onClick(widget => widget.triggerCommand("closeThisPane", { ntxId: widget.getNtxId() }));
+    }
+}